Calcifying tendinitis: a new concept of its pathogenesis

Area of Science:

• Orthopedics
• Pathology
• Musculoskeletal Research

Background:

• Calcifying tendinitis is a common condition affecting tendons, particularly the rotator cuff.
• Current understanding suggests degeneration precedes calcification (dystrophic calcification).

Purpose of the Study:

• To investigate the pathogenesis of calcifying tendinitis.
• To re-evaluate the role of degeneration in the development of calcific deposits.

Main Methods:

• Clinical and morphological investigations.
• Analysis of 46 surgically treated cases of calcifying tendinitis.

Main Results:

• No evidence of active or healed degenerative processes was found.
• Affected tendons transformed into fibrocartilage, predisposing to calcification.
• A distinct resorptive phase of calcification was observed, involving phagocytosing cells and vascular proliferation.
• Severe pain correlated significantly with histological signs of resorption.

Conclusions:

• The pathogenesis of calcifying tendinitis may not involve degeneration as previously thought.
• A unique pathway involving fibrocartilaginous transformation and a resorptive phase is proposed.
• Calcifying tendinitis should be considered a distinct disorder of the musculotendinous cuff.